(MAINT) Update `get-server` docs
(MAINT) Update `get-server` docs

Update the `get-server` docs to mention that the two-argument
version gets the server configured for the route with the
specified id.

fpringvaldsen/trapperkeeper-webserver-jetty9,puppetlabs/trapperkeeper-webserver-jetty9,puppetlabs/trapperkeeper-webserver-jetty9,rlinehan/trapperkeeper-webserver-jetty9,fpringvaldsen/trapperkeeper-webserver-jetty9,rlinehan/trapperkeeper-webserver-jetty9,camlow325/trapperkeeper-webserver-jetty9,camlow325/trapperkeeper-webserver-jetty9